The stars of "Perks of Being a Wallflower" present an award onstage during the 2012 MTV Movie Awards held at Gibson Amphitheatre on June 3, 2012 in Universal City, California. (Kevin Winter/AFP/Getty Images)

LOS ANGELES — "The Perks of Being a Wallflower" may have always been meant for the big screen.

After all, the 1999 cult novel's author Stephen Chbosky was a filmmaker before he turned to books, and has adapted "Wallflower" into a screenplay that hopes to capture the angst and excitement of being a high school misfit, the Los Angeles Times reported.

The trailer, released Monday, showcases the film's promising young cast, including "Harry Potter" star Emma Watson as Sam and "We Need to Talk About Kevin's" Ezra Miller as Patrick, who befriend Charlie (Logan Lerman) as he attempts to "turn things around" at the start of a school year following his best friend's suicide, Entertainment Weekly reported.

“I never thought I’d make another high school-esque movie,” Watson, who is looking to break out of her defining role as the Potter series' know-it-all Hermione Granger, told MTV. “And here I am as this coming-of-age, American, teen (film). But it’s very witty, it’s very funny, and it’s very moving.”

Chbosky said that though he received several offers to turn the book into a movie over the years, he turned them down until he could direct it himself, he told the New York Times.

“It was so personal,” Chbosky said. “I’ve seen the effect the book has had on certain kids who’ve seen bad things. Some of their stories, which they’ve told me in letters, would break your heart. I don’t need the money. What I need is for that 14-year-old kid to know they have a chance.”

The film, rated PG-13 after a battle with the Motion Picture Association brought it down from its original R rating, will be in theaters on September 15, the LA Times reported.